Can anyone please explain the graphics around the speedo in analog format? In reverse I get a yellow band inside the black , in park I get red, in drive I get just one black circle, in sport I get red plus the black. I swear it chages from time to time as well. Actually, last night I got nothing but the black circle and the pionter with no numbers whats so ever, this morning the numbers were back! What is the "back" button under the display screen do? I find nothing in the book to explain what is does or what it is for. Thanks